Effects of the whole seed and a protein isolate of faba bean (Vicia faba) on the cholesterol metabolism of hypercholesterolaemic rats

• Published in: British journal of nutrition 2001-05, Vol.85 (5), p.607-614
• Main Authors: Macarulla, M. Teresa, Medina, César, Diego, M. Aránzazu De, Chávarri, M., Zulet, M. Ángeles, Martínez, J. Alfredo, Nöel-Suberville, Catherine, Higueret, Paul, Portillo, María P.
• Format: Article
• Language: English
• Subjects: Analysis of Variance; Animals; Biological and medical sciences; Carbohydrates; Caseins - metabolism; Cholesterol; Cholesterol - metabolism; Diet; Dietary Proteins - administration & dosage; Disorders of blood lipids. Hyperlipoproteinemia; Faba bean; Fabaceae; Feces - chemistry; Hydroxymethylglutaryl CoA Reductases - metabolism; Hypercholesterolaemia; Hypercholesterolemia - metabolism; Legumes; Lipids - analysis; Liver - chemistry; Liver - metabolism; Low density lipoprotein; Male; Medical sciences; Metabolic diseases; Metabolism; Methods; Nutrition; Plants, Medicinal; Protein isolate; Proteins; Rats; Rats, Wistar; Seeds; Soybeans; Steroids; Triglycerides - blood
• ISSN: 0007-1145; 1475-2662
• DOI: 10.1079/BJN2000330

The aim of the present work was to analyse the hypocholesterolaemic efficiency of a Vicia faba-protein isolate in relation to the intact legume. In addition, the mechanisms underlying the effects of this isolate were investigated. Hypercholesterolaemic rats were divided into three groups (n 10×3) and fed high-fat diets rich in cholesterol-containing casein, whole seeds of Vicia faba or the protein isolate of faba beans as protein source, for 2 weeks ad libitum. The protein isolate was prepared by isoelectric precipitation and spray dried. Analyses of serum, liver and faeces, as well as of the activity of hepatic 3-hydroxy-3-methylglutaryl (HMG)-CoA reductase, were assessed by enzymatic methods. The rats fed on Vicia faba diets showed significantly lower body weights and energy intakes than rats fed on casein diets. The whole-seed diet induced a significant reduction in plasma triacylglycerol. Feeding rats on diets containing faba bean seeds, or the protein isolate, induced a significant decrease in plasma (LDL+VLDL)-cholesterol but not in HDL-cholesterol. Hepatic cholesterol and triacylglycerol were also reduced. The hypocholesterolaemic effects of Vicia faba were not the result of a reduction in cholesterol synthesis as assessed from HMG-CoA reductase activity, but the result of an increase in steroid faecal excretion. The faba bean-protein isolate obtained under our experimental conditions was useful in improving the metabolic alterations induced by feeding with a hypercholesterolaemic diet compared with casein. The effectiveness of the whole seeds was higher than that of the protein isolate.